Development of advanced technologies for enhancing obstacle-negotiation capabilities in mobile robots

Obstacle negotiation is one of the major challenges for mobile robots, particularly in environments where they must operate on uneven terrain or encounter physical barriers such as stairs, debris, or rough ground. Practical applications for such robots range from humanitarian assistance to logistics and inspection of hazardous or hard-to-reach environments. Although various technological approaches have been developed and successfully implemented, there is still a need to enhance robots’ ability to adapt to a wide range of complex obstacles, ensuring greater operational efficiency and safety. This thesis focuses on the analysis and development of innovative technologies to improve robots’ ability to overcome different types of obstacles. The primary goal is to enhance the robots’ capability to operate in challenging environments and ensure smooth and safe movement even in the presence of physical barriers, thus contributing to the advancement of mobile robotics. The first part of the thesis presents a systematic review of the scientific and engineering literature on stair-climbing mechanisms is given. It provides concise descriptions of the mechanisms and operating methods, highlighting the advan tages and disadvantages of various climbing platforms. To quantitatively assess system performance, several metrics are introduced. Using these metrics, it be comes possible to compare vehicles with different locomotion modes and charac teristics, offering researchers and practitioners valuable insights into stair-climbing vehicles and enabling them to select the most suitable platform for transporting people and heavy loads up staircases. The second part of the thesis aims to propose a rigorous analysis approach to study what happens when different kind of rubber belts or tires are in contact with a corner edge and what forces are exchanged between these two elements. A general introduction is given by mainly focusing on the scientific literature lack of a comprehensive wheel-obstacle contact model for the step-climbing problem. Then the importance of considering tire deformation has been emphasised and a novel approach to wheel-obstacle contact mechanics is given. A description of the test bench specifically developed for this work is provided along the experimental results for two cases of flat belt and tire patch. The third part of the thesis presents experimental results on the behavior of a conventional pneumatic tire clearing a step-obstacle, alongside an analytical model developed to analyze the interaction between a deformable tire and the corner edge of a step-obstacle. Finally, the ”XXbot” concept is developed. The thesis proposes a specialized model that predicts how the system will move based on the terrain profile. Stair climbing simulations were then performed using multibody simulation software MSC-Adams, and the results are presented to demonstrate the effectiveness of the proposed vehicle. The findings indicate that the robot can be adapted for various applications, such as stair-climbing wheelchair platforms.